Quote "I remember hearing TV scare stories about people driving around in cars and gathering personal data from outside your house! Or is that something totally different? "
Personal data can be obtained in many ways , taking utility bills bank statements out of your rubbish bag or making an enquireing phone call pretending to be your bank and asking some usual security questions. so many ways to gather information and so many ways in which it can be used.
but yes connecting to an unsecured wireless router is one of them , Always try to ensure your router is password protected , and as further security tip make the passwords something with letters and numbers , upper and lower case , even simbols for greater security. just please do remember what your passwords are you may need them yourself one day.